Trolley wire safety device



Dec. 17, 1940. I GENTER 2,225,559

TROLLEY WIRE SAFETY DEVICE Filed June 15, 1940 INVENTOR 24 ATTORNEY Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE TROLLEY WIRE SAFETY DEVICE Pennsylvania Application June 15, 1940, Serial No. 340,695

2 Claims.

This invention relates generally to trolley line equipment and more particularly to apparatus for connecting adjacent trolley sections through a protective device.

This invention may be advantageously employed in mine trolley systems wherein the branch entries, butt entries and rooms may be independently isolated from the face and main hauling entries when an electrical fault occurs due to a short circuit caused by a cave-in or failure of mining equipment. By electrically isolating the section in which the fault occurs other parts of the mine may continue to function undisturbed by the isolated failure.

The protective device is designed to isolate the faulty section when subjected to an overload materially less than the setting of the main circuit breakers feeding the mine trolley system. Thus the main circuit breakers are not required to function unless the fault is not cleared.

The principal object of this invention is the provision of a protective device for opening the circuit of a trolley section to isolate it from the rest of the system when it is subjected to a predetermined overload.

Another object is the provision of a protective device for isolating a trolley section adjacent its source of electrical supply when it is subjected to a predetermined overload.

Another object is the provision of a protective device suspended with the trolley equipment for isolating a trolley section when an electrical fault occurs therein.

Another object is the provision of a trolley frog for connecting a branch or spur trolley line which is equipped with protective means for isolating the branch or spur in case of an electrical failure therein.

Other objects and advantages appear hereinafter in the following specification and claims.

In the accompanying drawing a practical embodiment illustrating the principles of this invention is shown wherein:

Fig. 1 is a plan view of the under or collector engaging surface of a trolley frog comprising this invention.

Fig. 2 is a plan view of the upper surface of the trolley frog shown in Fig. 1.

Fig. 3 is a side elevation of the trolley frog reversed from that shown in Fig. 1.

Fig. 4 is an end elevation taken on the line 4-4 of Fig. 2 showing the fuse supporting structure above the frog casting.

Fig. 5 is a longitudinal sectional View taken on the line 5-5 of Fig. 2.

Fig. 6 is an enlarged sectional view taken on the line 66 of Fig. 2 showing the interlocking between the clamp and the frog casting.

Fig. 7 is an enlarged sectional view taken on the line 'l-'l of Fig. 3 showing the clamp in posi- 5 tion for removal.

Referring to the drawing, the frog casting It] comprises the ceiling plate H with integral depending track or current collector engaging portions I2, l3 and I4 and the depending guide 10 flanges l5 along the marginal sides. The ends of the ceiling plate slope upwardly as indicated at l6 and the ends of the guiding flanges flare outwardly as shown at I! for receiving and guiding the spaced flanges of the trolley wheel or shoe as it passes over the frog. The outwardly extending lugs l8 on the sides of the plate II are provided with openings to receive means for supporting the frog.

The metal forming the track sections I2, [3 and I4 is grooved from above as shown as IQ for receiving the continuous trolley wire 20 as shown in Fig. 2. This type of frog can be inserted or removed from any position along the hauling entries without disturbing the main trolley line.

The trolley wire clamps 2| and 22 are C-shaped castings having downwardly and inwardly projecting flanges 23 arranged to receive the outwardly projecting flanges 24 adjacent the top of the grooved track sections l2, I3 and i4. These clamps are provided with a centrally disposed threaded hole for receiving the set screws 25 which are screwed down against the trolley wire, raising the inwardly projecting flanges 23 into engagement with the outwardly projecting flanges 24. If there is insufficient head room for the set screws these clamps may be secured by means of a wedge 26 as illustrated in conjunction with the clamp 22.

The inwardly projecting flanges of the clamp 21, which secures the branch trolley wire 28 to the outer portion of the depending track section [4, are provided with an upwardly extending lug 30 arranged to slide under the flanges 24 until they mate with the vertical slots 3| in said flanges as shown in Fig. 6. When the clamp 21 is raised into clamping position by screwing in the set screw 25, the lugs 30 become engaged in the slots 3| and prevent relative movement between the clamp and the frog. The set screw bites into the dead end section 28 of the trolley wire branch line and secures it to the frog. It is not necessary to provide this interlocking means in the clamps 2| and 22 unless the trolley wire 20 is severed and not in one continuous piece as shown.

32 indicates the branch or spur casting which carries the outer portion of the depending track section l4 and which is electrically insulated from the main body of the frog casting H]. The casting is connected with the main frog by the track section 33 which is preferably made of a mechanically strong insulating material. A hard wood which has been treated to be impervious to moisture has been found to be suitable for this purpose. The ends 35 of the insulating track section 33 are reduced to fit into the grooves I9 in each of the track sections I4 of the castings and provide a smooth underrun for the current collector. These ends are secured to the casting by the transversely disposed pins '34.

Aligned upwardly projecting brackets 35, preferably of T-shape cross section, are formed integral with the main frog casting Ii] and the spur casting 32. A pair of bars 31 made. of suit able insulating material such as fiber, Bakelite or a plastic material is provided for securing the castings together. The ends of these bars are mounted on the opposite faces of the .web portions of the brackets and are secured thereto by the bolts 38. The bars 31' and the insulating section 33 rigidly secure the spur casting to the main'body of the frog casting and maintain the track sections M in alignment.

. T e heads of the brackets 36 are provided with flat tops disposed in the same horizontal planes for carrying the double clips 40 which are engaged by the terminal blades 4! of the fuses 42. These clips comprise upper and lower leaves 43 held in proper relative position by the spacer blocks M. Each pair of leaves is secured in place on the bracket by two tap bolts 45 which extend through the leaves and the spacer block into tapped holes in the head of the bracket.

The fuses 42 thus provide a parallel electrical connection between the main frog casting HI and the spur casting 32 and are removable horizontally from the fuse clips 49. There is very little head room above the mine trolley apparatus and it is therefore necessary to mount the fuses as closely as possible to the frog casting and leave sufficient space in which to grasp and withdraw each fuse.

It may be desirable to entirely isolate a section temporarily. This may easily be accomplished at the frog along the main entry by withdrawing bothfuses.

Frequently a water pump or ventilating fans are operated from the trolley system at the ends of the branch or butt entries. This character of equipment ordinarily operates continuously and is inspected periodically, yet these entries may have very little or no coal removing operations requiring mining machinery which draw a heavy electrical load. In the latter instance the capacity of the fuses need only be suflicient to properly protect the pump and fan equipment. Thus the branch trolley lines may be used in abandoned sections which must be kept open until the pillars are drawn.

I claim:

1. A trolley wire protective device comprising a pair of members arranged to be connected to the spaced ends of an interrupted trolley wire line, a track section of electrical insulating material providing with said members a continuous contact surface for the current collector, double fuse clips each comprising a pair of leaves held in spaced relation provided with a pair of openings forms a continuous contact surface for a current collector, an upstanding T-shaped bracket on each castinghaving a head and web portion, said brackets being positioned so that their Webs lie in a common plane, a pair of insulating bars secured on opposite faces of the web portions of the brackets, the heads of said brackets carrying double fuse clips each comprising a pair of horizontally disposed leaves extending, on both sides of the head and held in spaced relation by a washer, a pair of aligned openings in the leaves and the washer, tap bolts inserted through said I openings into threaded holes in the top of the heads of said brackets, and a pair of fuses having their opposite terminals engaging in said clips for completing the electrical circuit between the ends of said trolley lines.

ALBERT H. GENTER. 

